At least some example embodiments of the inventive concepts relate to a voltage regulator and/or devices including the same. For example, at least some example embodiments relate to a voltage regulator for suppressing overshoot and undershoot and/or devices including the same.
With the rapid development of the mobile devices, mobile devices may have increasingly advanced functionality; however, the capacity of batteries of the mobile devices is limited. Therefore, manufacturers are focusing on increasing the use time of mobile devices by affectively using the battery rather than attempting to increase the capacity of the battery.
A mobile device usually includes a low-dropout (LDO) regulator which is provided with an operating voltage from a power management integrated circuit (IC) included in the mobile device. The LDO regulator may convert the operating voltage into an output voltage utilized by a semiconductor chip included in the mobile device. To convert the operating voltage to the output voltage, the LDO regulator may need to sufficiently secure a dropout voltage, i.e., a difference between an input voltage and the output voltage in order to correctly generate the output voltage.
When the dropout voltage is too small, the overall feedback loop gain of the LDO regulator may decrease, thus causing a large error in the output voltage of the LDO regulator. Although it is advantageous in design to sufficiently secure the dropout voltage, power efficiency of the LDO regulator may decrease as the dropout voltage increases. When there is a rapid change in an output current of the LDO regulator, i.e., a current used at a load connected to the LDO regulator; overshoot and undershoot may occur in the output voltage of the LDO regulator.